6421997544000 has 448 divisors, whose sum is σ = 21616064870400. Its totient is φ = 1679509248000.

The previous prime is 6421997543977. The next prime is 6421997544013. The reversal of 6421997544000 is 4457991246.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 621618835 + ... + 621629165.

It is an arithmetic number, because the mean of its divisors is an integer number (48250144800).

Almost surely, 2^{6421997544000} is an apocalyptic number.

6421997544000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6421997544000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10808032435200).

6421997544000 is an abundant number, since it is smaller than the sum of its proper divisors (15194067326400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6421997544000 is a wasteful number, since it uses less digits than its factorization.

6421997544000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10859 (or 10839 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 51.

The spelling of 6421997544000 in words is "six trillion, four hundred twenty-one billion, nine hundred ninety-seven million, five hundred forty-four thousand".